Illustration of a tub of weight gainer powder.

The Best Bulking Supplements for Skinny Guys, Ectomorphs & Hardgainers

Over 5,000 shares and 500 comments later, here’s our revised supplement guide for skinny guys who are trying to build muscle in time for last summer. We’ll cover everything you need to know about supplements that speed up muscle growth, such as creatine, and we’ll go over the supplements that help hardgainers bulk up, such as weight gainers/mass gainers.

To do this, we need to evaluate the research—all of the research. It’s easy to claim that a supplement is effective by showcasing the results of a single study. Still, when we dig into the entire body of evidence, surprisingly few supplements remain standing. This article tries to do that, favouring systemic reviews and meta-analyses over the latest (and often controversial) research.

We’ve also been in the trenches with this. I’ve personally used these supplements to gain sixty pounds at 11% body fat, Marco has used them to gain nearly seventy pounds at 10% body fat, and we’ve recommended them to nearly 10,000 members of the Bony to Beastly Bulking Program, as well as the 500,000 people who have read this article.

Disclaimer: We recommend consulting with your physician before taking supplements. We’ll reference authorities (such as the Mayo Clinic) and clinical research, but keep in mind that these supplements may interact poorly with certain pre-existing health conditions.

Before and after illustration of a skinny hardgainer ectomorph becoming muscular.

Ectomorphs Benefit From Different Supplements

As so-called “ectomorphs,” our goal is the exact opposite of everyone else. They want to lose weight; we want to gain it. This means that we’re using a different set of criteria to evaluate the effectiveness of our supplements. More calories? Good. More weight gain? Good. Does it increase appetite? Perfect.

Illustration of a skinny guy becoming muscular from doing biceps curls.

For example, consider branched-chain amino acids (BCAAs). BCAAs are a trendy ingredient in muscle-building supplement cocktails. However, BCAAs are simply a calorie-light version of protein powder. A standard serving of whey protein powder contains the same nutrients as a standard scoop of BCAAs. The difference is whey protein also contains many other amino acids and nutrients, making it far higher in calories.

If someone is looking for a low-calorie alternative to protein powder, BCAAs are a good choice. However, as hardgainers, we’re desperately trying to eat more calories to gain weight. And we don’t just want the three branched-chain amino acids; we want all of the amino acids. After all, the more amino acids there are in a protein source, the better it will build muscle (study).

BCAAs are also popular with guys who practice intermittent fasting. This is because having BCAAs during the fasting period is thought to be a way to stimulate muscle growth without breaking the fast. However, intermittent fasting makes it harder to gain weight, so it’s the same issue all over again.

Anyway, this means that whey protein is far better for our goals. It’s cheaper, healthier, has the ideal blend of all the amino acids, and has more calories. We can even take this line of thinking one step further. When it comes to whey protein, whey protein isolates are usually considered the gold standard because they’re a purer source of protein—more of the carbs are processed out. On the other hand, whey protein concentrates aren’t as refined, leaving more carbs mixed in with the protein. It’s a higher-calorie and more nutrient-dense alternative. And that’s great for us.

This is all to say that when looking at supplements, we need to keep our specific goal in mind: we want bulking supplements.

Do Ectomorphs Need Supplements To Bulk?

The short answer is no; you don’t need supplements to gain weight, build muscle, build it quickly, or build it leanly. You can build plenty of muscle simply by following a good hypertrophy workout program, eating enough protein and carbs, eating enough calories, and getting plenty of good sleep.

Furthermore, without those getting fundamentals down, supplements are a waste of money. After all, even if you find a supplement that can boost your results by 50%, an extra 50% on top of nothing is still nothing.

If you’re a beginner, you’re going to experience a phenomenon called newbie gains, allowing you to build muscle quite fast during your first few weeks of working out. Your results may vary, of course, but beginners are often able to build muscle quite quickly:

Bony to Beastly Ectomorph Transformation: The Best Muscle-Building Supplements for Ectomorphs

Your muscle growth will taper off over the course of the year, but by then, you may have gained as much as 40 pounds. You may not even be skinny any longer.

If you aren’t lifting weights yet, I recommend getting a good bulking program and starting with that. You might even like our Bony to Beastly Bulking Program.

If you already know the fundamentals of building muscle, though, supplements can help you do a few things:

  • Supplements can make a bulking routine easier. For example, protein powder makes it easier to eat enough protein. Mix it with some water and you’re done. Protein powder also has the advantage of not being very filling, making it easier to eat enough calories.
  • Supplements can speed up the rate that you build muscle. For example, creatine will allow you to build muscle more quickly, meaning that you might able to gain your first twenty pounds of muscle in fifteen weeks instead of twenty.
  • Supplements can help keep your gains leaner. For example, by speeding up the rate that you can build muscle, creatine can also help you stay leaner. If more of the calories you’re eating are being used to build muscle, there are fewer leftovers to be stored as fat.
  • Supplements can improve consistency. For example, caffeine can help reduce fatigue, making it easier to hit the gym consistently. Caffeine is also addictive (which is both good and bad), so if you get in the habit of having it before lifting, you might become addicted to your lifting routine.

None of these things are essential, but they might make supplements worthwhile for you.

Simple Calories Outperform Fancy Ingredients

I don’t know about you, but the hardest part about building muscle for me is eating enough. Not the lifting, the eating. That’s not uncommon for us naturally skinny hardgainers, either. It’s common for us to have smaller stomachs and faster metabolisms, which can make it incredibly hard to eat enough calories to gain weight. That’s something we need to keep in mind as we pick our bulking supplements.

Illustration of a skinny hardgainer eating enough calories to gain weight.

First, bulking means eating more food, which means that we will get extra nutrients from all of that extra food. As a result, we don’t need to worry as much about supplementing with vitamins, minerals, and phytonutrients. Our bulking diet takes care of that for us.

Second, we want to prioritize supplements that help us get into a calorie surplus. Protein powders are rich in calories, easy on the appetite, and very quickly digested, making them great bulking supplements. This is even true of carbohydrate powders. For example, in this study, guys who added whey protein and maltodextrin into their diet gained an extra 7.5 pounds of muscle over the course of 8 weeks while simultaneously losing fat.

Mixing protein with maltodextrin makes a mass gainer shake. You can make them yourself, or you can buy them pre-mixed. What makes these mass gainers so effective is their density of calories, carbs, and protein. Furthermore, having all of those calories right after your workout, when your muscles are more insulin sensitive, will help you build a bit more muscle slightly more leanly (studystudystudy).

This “post-workout anabolic window” is often exaggerated in the muscle magazines, but there is indeed some benefit to having plenty of carbs and protein after working out. It’s especially helpful for us ectomorphs because lifting can sometimes blunt our appetites, which can cause us to fall behind on our calories. Having a post-workout shake solves that problem.

Now, to be clear, you can accomplish this same thing with chocolate milk. The important thing is that you get that influx of protein and carbs, not that you have a specific combination of supplements. In this case, the only advantage of using supplements is that it’s easier to pack a protein/carb shake in your gym bag than it is to pack a quart of milk. Aside from that minor inconvenience, though, milk can be fantastic for building muscle. In fact, there are a ton of great bulking foods.

Weight-gainer shakes help us eat more calories. You’ll be drinking the calories, they’re all quickly digestible, and they won’t take up much room in your stomach (studystudy). This makes downing 1000+ calories pretty easy (albeit unpleasant), and you can do it in a couple of gulps before heading home from the gym.

Some supplements do provide benefits that food cannot. We’re getting ahead of ourselves a little bit, but there is one supplement that doesn’t contain calories but can still boost muscle growth by as much as 50%—especially if you’re still fairly new to bulking up. It’s called creatine. You’ve probably heard of it.

These bulking supplements are affordable. They’re even affordable compared to buying chicken and rice at the grocery store. If there were fancier supplements out there that worked better than these, we’d tell you about them. But there aren’t. The basics tend to provide the best results. That’s why they’re the basics.

Okay, now onto the specific ingredients so that you can make your own workout shake. But again, I want to remind you that you should consult your doctor before taking supplements. As we mentioned above, although these supplements have quite a bit of evidence proving their effectiveness and even safety, that doesn’t mean that they’ll be safe for you as an individual. For example, supplements can interact poorly with certain health conditions.

The Very Best Bulking Supplements

Illustration of a tub of weight gainer supplement powder.

The three best bulking supplements for skinny guys are:

  • Creatine: speeds up the rate that we can build muscle, allowing us to bulk up more quickly and leanly.
  • Caffeine: gives us the kick in the glutes that we need to get to the gym and lift like a Beast.
  • Whey protein: makes it easier to hit our daily protein goals without feeling stuffed.

Let’s go into each one in more detail.


Creatine is the most famous bulking supplement, and with good reason (study). Hundreds of studies prove it increases muscle growth and strength gains (studystudystudy, study). The study designs are wonderfully simple, too. If you mix creatine into someone’s morning coffee, they’ll reliably gain more muscle and strength.

Is Creatine Safe / Healthy?

The other benefit to creatine is that it’s been studied for several decades now and has proven itself to be remarkably safe and healthy (study, study, study). As a result, authorities such as the Mayo Clinic list creatine as “generally safe” and list its uses as follows:

Your body converts creatine to phosphocreatine and stores it in your muscles, where it’s used for energy. As a result, people take creatine orally to improve athletic performance and increase muscle mass.

However, they do note that “people who have kidney disorders or people at risk of developing kidney disease should talk to a doctor before taking creatine due to concerns that the supplement might cause kidney damage.”

If you’re healthy, the only thing you need to be mindful of is drinking enough water. Creatine pulls fluid into your muscles, so you might give yourself a stomach ache if you don’t have enough fluid available. This is why creatine is normally mixed into drinks (such as water or protein shakes).

How Does Creatine Work?

Creatine improves muscle growth in two main ways:

  • It helps your body replenish ATP, which is the type of fuel that you use when lifting weights. This allows you to eke out a couple of extra reps, stimulating a little bit more muscle growth.
  • Creatine also improves muscle protein synthesis and glycogen storage. This means that not only will you build more muscle via your training, you’ll also get more muscle out of the food that you’re eating.

How Much Extra Muscle Does Creatine Build?

One of the most common questions we get is what kind of results to expect when taking creatine. How much weight will you gain? How much extra muscle will you build? That’s hard to answer because it seems to depend on how much creatine you already have in your system. Some people respond strongly to it, gaining several pounds during their first couple weeks of taking it. Other people don’t notice any results at all. Still, there are quite a few studies, and so it’s easy to find an average.

This 8-week study investigated what would happen if beginners were put on a workout program and given either a carb shake or a carb + creatine shake.

  • The group who got the carb shake gained 6 pounds of muscle.
  • The group who got the carb shake + creatine gained 9 pounds of muscle.

So, in this case, creatine boosted muscle growth by 50% in beginners who were new to lifting weights, which wound up giving them an extra 3 pounds of muscle. We’d expect that effect to slow as their muscles become fully saturated with the extra creatine, but even then, it would still give them a slightly faster rate of muscle growth.

Image showing the results of a guy before and after taking creatine.
Jared started taking creatine at the beginning of this transformation.

By the time someone is looking at before and after photos, it’s hard to discern how much the results come from the creatine. It’s a package deal. You lift weights, eat enough calories, eat enough protein, supplement with creatine, and get great results. How much of that is from the creatine? It’s hard to say. But maybe a couple of pounds.

Does Creatine Affect Fat Gains?

Yes, creatine tends to reduce fat gains while bulking. Creatine will improve insulin sensitivity in your muscle cells. More insulin sensitivity in your muscle cells means that more of the calories you eat are used to build muscle instead of being stored as fat. This can help to prevent fat gain while bulking.

Most of us ectomorphs naturally have good insulin sensitivity. Lifting weights will improve that insulin sensitivity, and gaining more lean mass will improve it further. It’s not something we necessarily need extra help with. But any help is welcome.

Should You “Load” Creatine?

If you take 5 grams of creatine every day, it will take around a month for your creatine levels to rise to max levels. This will make your bulking progress seem nice and smooth since your muscles will also be pulling in that extra fluid as you bulk up. This has proven to be wonderfully effective for building muscle.

However, fast and steady wins the race. To cut that loading period down to a week, you could take four 5-gram doses each day for a week. At that point, you’d then drop your intake down to a daily 5-gram dose. However, it’s unclear whether there’s a muscle-building advantage to loading up quickly like that. Furthermore, the risk of becoming dehydrated goes up. As a result, we recommend taking 5 grams every day instead. It’s just as good for building muscle, and there’s less risk of having unpleasant side effects (such as stomach cramping).

Are You a Creatine Non-Responder?

Roughly 25–33% of people don’t respond to creatine at all (study, study). These people are called creatine non-responders. It’s not entirely clear why some people respond to creatine and others don’t, but it might have to do with how much meat people have in their diet. If you’re a vegan or vegetarian, creatine seems to have a stronger effect. If you eat a lot of meat, it may have a weaker effect.

This is a good example of how the results that you get from supplements can vary. Some people will have a stronger-than-average response to creatine; others will be total non-responders.

Here’s a good brand that makes simple creatine monohydrate


To build muscle, we need to work out. To work out, we need to actually get to the gym and do the damn exercises. Even when we’re tired and sore. Even when we’d much rather be playing Elden Ring. That’s where caffeine comes in. If you’re feeling low, having a bit of caffeine can make you feel, well, a little bit high. That way you can get to the gym and give your workouts your all, fighting to outlift yourself.

Milo of Croton lifting a calf that grows into a bull, illustrating the principle of progressive overload.

Here’s the thing, though. Caffeine can be an “ergogenic” supplement—a supplement that improves power, stamina, and recovery. It can help us train harder. But to get those benefits, you’d need to supplement with A LOT of caffeine. If you’re an average skinny dude, you’d have to take like 300+ milligrams of caffeine to get a measurable boost in exercise performance. That’s the equivalent of two large energy drinks. It’s not nearly enough to kill you, but it might be enough to interfere with your overall energy levels and sleep. Plus, caffeine can be addictive.

And we’re in this to be bigger, stronger, and healthier, right? If a supplement interferes with that, my inclination is to ditch it. Or, in this case, to scale the dosage back down into the normal range.

How to take caffeine: we recommend having caffeine like people normally have it. Something like 50–150mg. The amount you’d find in a cup or two of tea or coffee. Personally, I try to stick with espresso, Americanos, and cold brews… but I’ll sometimes have an energy drink or pre-workout if I’m training earlier in the day and want that extra boost of energy.

Whey Protein

Whey is an easily digested protein found in milk. It’s processed fairly minimally, allowing it to retain many vitamins and minerals. Many nutritionists and dieticians consider it a whole food, as they would with other minimally processed dairy products, such as cheese and yogurt. Because of its high protein content, though, whey protein powder is nutritionally more similar to a chicken breast.

Why is Whey Protein Good for Bulking?

Our muscle fibres are constructed out of the protein we eat, so a shortage of protein limits the amount of muscle we can build (study, study). If we’re gaining weight, but our rate of muscle growth is limited, then we’ll be forced to store body fat instead. As a result, not consuming enough protein can cause us to gain less muscle and more fat. Not ideal.

However, although 0.8g/lb/day is the true minimum amount of protein that’s needed to optimally stimulate muscle growth, we recommend aiming a little higher. The main reason for that is because most people overestimate the amount of protein they eat. It’s not their fault, either. Oftentimes the nutrition label or calorie calculator is wrong. For example, an interesting (indie) study looked into the top brands of whey protein. The study went viral because it showed that many popular protein supplements contained much less protein than they claimed. The same is true with nutrition labels.

How Much Whey Protein Can You Have Per Day?

Most people can get away with having 2–3 scoops of whey protein per day without running into any issues. That doesn’t mean that you should have that much whey protein every day, but if it’s helping you hit your protein targets, then it can certainly help you gain muscle faster.

To gain muscle as quickly as possible, you need roughly 0.8 grams of protein per pound bodyweight per day. For a 150-pound man, that’s 120 grams of protein per day. Less than that, and you’ll be building muscle at a reduced pace. So once you’ve hit that target, you don’t need more whey protein. More than that isn’t necessarily harmful, mind you. It just won’t cause any extra muscle growth.

Now, as we mentioned above, where you get your protein is up to you. Maybe your diet is naturally rich in protein, so you don’t even need whey at all. Or maybe you save the whey protein for your post-workout shakes. On the other hand, perhaps your diet is low on protein, so you have a couple scoops every day (adding around 55 grams of protein to your diet). That’s quite common.

Anyway, as for how much whey protein you can have per day, the important thing is simply having enough protein in your diet overall. Whether you choose to eat more chicken, greek yogurt, whey protein, pea protein, or pumpkin seeds is up to you. All will work similarly well.

Why is Whey the Best Protein Powder?

Whey digests extremely quickly and efficiently, and it contains the perfect blend of amino acids for building muscle. This means that whey protein provides all the benefits of BCAA supplements and HMB supplements, all for a fraction of the price, and while containing several times as many calories, vitamins and minerals. Whey is also especially high in the amino acid leucine, which Layne Norton, PhD, proved was important for stimulating muscle growth. (Pea protein is also high in leucine, for the record.)

Because of how effectively whey protein stimulates muscle growth, and because of how efficiently digested it is, it’s a great type of protein to take before, during, or after a workout (studystudy). This is even more important when doing full-body workouts, as you’ll be stimulating muscle growth throughout your entire body.

Then, if you really want to kick things up a notch, you can combine whey protein with an efficiently digested high-calorie carb source, such as maltodextrin (study). This is why most commercial weight gainers will combine these two ingredients. You could, of course, buy a pre-mixed weight-gainer, but most of us find it helpful to have the two ingredients available separately so that we have more control over our bulking macros.

So to summarize, whey is a great bulking supplement cause:

  • It’s calorically dense.
  • It’s easy on the appetite.
  • It’s quick to prepare and consume.
  • It’s fairly affordable per gram of protein.
  • It tastes better in smoothies than tuna.

So if you’re struggling to gain weight, a tub of whey can go a long way.

Here’s a good whey protein supplement

Are Weight Gainers Good for Skinny Guys?

Yes, weight gainers can help skinny guys gain build muscle and gain weight. Most skinny guys have a hard time eating enough to gain weight and, as you might be able to guess, weight gainers are packed full of easily digested calories, blowing the bottleneck off of our ability to build muscle. As a result, weight gainers can be quite helpful.

The more nuanced answer is that weight gainers are just a source of highly processed carbs and protein powder. The protein generally comes from whey protein, and the carbs tend to come from maltodextrin. Fancier weight gainers might use grounds oats instead of maltodextrin, but the effect is similar. And then to make them taste better, there’s usually some artificial sweeteners and flavours, which is fine.

All of these ingredients are good for building muscle and they’re all incredibly easy to digest. That’s great for bulking up. However, weight gainers aren’t rich sources of micronutrients, so if we get too many of our calories from them, we might fail to get the vitamins and minerals that we need to maintain our general health. Similarly, mass gainers tend to be low in fibre, so if we go overboard with them, it’s possible that they could have a negative long-term impact on our digestive systems.

What tends to work well for us and our clients is to use weight gainers as post-workout shakes, not as meal replacements. This means that we have three big 1,000-calorie weight-gainer shakes every week after lifting weights. The other four days of every week, we rely on whole-food smoothies instead.

In those smoothies, we get our carbs from oats and fruits instead of maltodextrin. For protein, we often use yogurt and whey protein. That’s going to ensure that we’re getting the vitamins, minerals, fibre, prebiotics, and probiotics that we need while still hitting our daily calorie targets.

To have this flexibility, we generally recommend buying your whey protein and maltodextrin separately and making your own weight gainer supplements with the macros that you need in the moment. That way you can use the maltodextrin on workout days, and then on rest days, you can use just the protein powder. (More on maltodextrin in a minute.)

Bulking Supplements for Vegans 

There are a few good bulking supplements that are especially helpful for vegans. Our article about vegan bulking has a full list of recommended supplements, as well as general best practices while bulking on a plant-based diet. Here’s a quick rundown, though:

  • Vitamin B-12: The most common deficiency that vegans run into is a vitamin B-12 deficiency (studystudy). As a result, most experts recommend that vegans take b–12 vitamins. 
  • Creatine: The more creatine you have in your muscles, the more quickly you’ll be able to build muscle (meta-analysis). Since creatine is naturally occurring in meat, vegans tend to consume much less of it (studystudy), and thus have more to gain by supplementing with it (study). All creatine supplements are 100% plant-based, too, so there’s no worry there.
  • Calcium and zinc: Many plants contain calcium and zinc, but those same plants often contain phytates and oxalates as well, which reduces nutrient absorption (studystudy). It’s not that plant-based diets aren’t rich in these nutrients, it’s just that vegans need to eat more of them. Mind you, bulking means eating an abundance of food and calories, so this won’t necessarily be a problem.
  • Vitamin D: Most people are deficient in vitamin D, especially during the winter (study). Vitamin D is notable for vegans, though, because they don’t eat dairy that’s fortified with it (studystudy). That means that they may need to supplement with it directly. When doing so, keep in mind that D3 is the most effective form of Vitamin D and that only lichen-based D3 supplements are plant-based.
  • Beta-alanine: Beta-alanine is a mediocre bulking supplement overall, causing unremarkable increases in muscle mass in most people (study). However, since plant-based diets are lower in carnosine (study), and since beta-alanine increases muscle carnosine content, this might be a more worthwhile supplement for vegans (study).
  • Carnitine and taurine: Plant-based diets are also lower in carnitine (study) and taurine (study), which are common ingredients in pre-workout supplements. However, these supplements aren’t generally considered essential for vegans.
  • Omega-3 fatty acids: vegan diets are lower in omega-3 fatty acids (study), and there’s preliminary evidence that getting enough omega-3s might improve body composition (study). It’s also a good idea to have omega-3s in your diet just from a general health perspective.

Mediocre Bulking Supplements

Here are the supplements with a little bit of positive evidence behind them. Most of these supplements will indeed help us build muscle more quickly, but the effects tend to be quite minor or situational.


Most weight-gainer supplements are a combination of protein powder and carbohydrate powder. Usually, they’ll use whey and maltodextrin, but you could also make one out of, say, pea protein and ground oats.

The first reason that maltodextrin is so popular in weight-gainer shakes is that it’s incredibly easy to digest. It quickly breaks down into glucose, which is the body’s preferred form of energy overall, as well as what our muscles use for fuel (in the form of glycogen). So, given how efficient of a short-term energy source it is, it’s quite unlikely to be stored as fat. (Your body much prefers storing fatty acids as body fat.)

The second reason that maltodextrin is popular is that it’s so unbelievably cheap. Given how cheap it is, you’d almost think you were buying a tub of flour… and you’d be almost correct! In fact, the only significant difference between maltodextrin (corn powder) and flour (grain powder) is that maltodextrin can be eaten raw, whereas flour must be cooked first. This allows you to mix it into protein shakes.

That study in the creatine section is said to have produced the highest non-steroidal increases in lean mass ever seen in the placebo group. The study was technically studying creatine, so the researchers were surprised when the placebo group, who was getting corn powder, saw a massive increase in muscle mass, gaining 6 pounds of lean muscle in just 8 weeks. (Part of this is due to the participants being put on a fairly good lifting program, but still!)

Will Maltodextrin Make You Fat?

As an ectomorph who’s lifting weights and trying to build muscle, getting a good portion of your calories from starchy carbohydrates is actually a pretty good way of minimizing fat gains. Guys tend to build muscle the most leanly on higher carb diets, and starches are a great type of carb for building muscle.

Lifting raises the insulin sensitivity in your muscle cells, especially in the two hours following your last workout and especially if you’re doing full-body workouts. This means that any surplus calories consumed within a couple of hours of an effective workout are more likely to be stored as muscle than fat.

To make absolutely sure of this, we consulted the most respected researcher in this field, James Krieger, Ph.D., who told us:

Post-workout carbohydrates shouldn’t cause you any trouble in the long run as you are extremely insulin sensitive after training. As long as you maintain a good diet, good activity, keep your body fat low, and your fasting blood sugar remains normal, then you should be fine.

James Krieger, PhD

Here’s an example of a simple maltodextrin supplement

Citrulline Malate

Citrulline malate is the best “pump” supplement on the market right now and it’s actually faring quite well in the research. When digested, it converts into arginine, which turns into nitric oxide, and which dilates your blood vessels, allowing you to pump more blood into the muscles that you’re training.

This enhanced muscle pump can improve the health of your blood vessels and increase muscle protein synthesis, which could certainly help an ectomorph gain a little bit more muscle. However, you can get much of this benefit simply from including some higher-rep sets in your lifting routine, which you should probably be doing anyway.

This isn’t quite a top-tier supplement, but you’ll see it in a lot of higher-quality pre-workout supplements, and that’s perfectly fine.


Beta-alanine is creatine’s little brother. Both supplements improve the number of reps we can eke out while lifting weights, and both supplements improve our ability to build muscle. It’s just that beta alanine has a much more minor impact.

You’ll find beta alanine in a lot of the better pre-workout supplements, and with good reason. In an interview with Jeremy Ethier, the leading muscle growth researcher, Dr Brad Schoenfeld, ranked beta alanine as one of the four best muscle-building supplements, alongside creatine, whey protein, and caffeine.

The ideal dosage seems to be around 3–5 grams per day taken at any time (similar to creatine). Be warned, though—it can make your skin tingle (paresthesia). Harmless, but strange.


Ashwagandha is an intriguing muscle-building supplement, and on that I have started consuming myself after looking through the research. The first study to make waves in the muscle-building world was this one, showing that ashwagandha can:

  • Speed up muscle growth
  • Increase strength gains
  • Reduce fat gains
  • Increase testosterone
  • Reduce cortisol

To give you an idea of the magnitude of these effects, the 8-week study found a 15% greater increase in testosterone and a 44-pound greater increase in bench press strength when compared to the placebo group. That’s amazing, but this is just one study, and none of the others are seeing results like this one.

If we look at a meta-analysis examining the overall body of evidence, we do still see benefits from supplementing with ashwagandha, but the effects are much less dramatic.

So ashwagandha may indeed help skinny guys build muscle. It might also help skinny-fat guys by improving their ability to build muscle while losing fat. And there doesn’t seem to be any negative side effects, even after several years and over a dozen studies. But the benefits aren’t dramatic.

Vitamin D

Vitamin D can increase our testosterone production if and only if we’re deficient in vitamin D. Most people are deficient in vitamin D, though, which makes this is a viable supplement for most people, especially during the winter.  

Keep in mind that Vitamin D won’t boost your testosterone production outside of normal ranges. However, for guys who don’t get enough sun, this can bring their muscle-building potential back to baseline. It’s a good supplement, but it’s situational, and getting more sunlight may be a better option anyway.

Fish and Krill Oil

Fish oil contains healthy fatty acids (DHA and EPA). which seems to improve muscle growth as a welcome side-effect. There are a few studies showing modest increases in muscle mass and small reductions in fat mass from fish and krill oil, and another study just came out showing that fish oil supplementation can slightly improve weight training performance (study). However, these effects are quite small.

Fish and krill oil are also surprisingly controversial supplements, and while most health experts do recommend consuming enough DHA and EPA, it’s still unclear exactly how we should approach supplementation.

Curcumin (aka Turmeric)

Supplementing with curcumin probably won’t increase your muscle growth, but a recent systematic review found that it reduces our overall inflammation without interfering with our recovery process, decreasing our muscle soreness and allowing us to handle higher training volumes with less fatigue. Curcumin also appears to be great for our general health and improves our digestion. These findings were mirrored in a second systematic review, meaning there’s quite a lot of evidence behind it at this point.

As a result, curcumin can be a great bulking supplement for skinny guys, making both our workouts and our bulking diets easier, as well as improving our general health. And it has no real downsides.

Underwhelming Bulking Supplements

Here are the bulking supplements that are overhyped or understudied. It’s possible that they might be good muscle-building supplements, but we just can’t say for sure yet. As more research comes out, we’ll continue updating this list.

Turkesterone (and Other Ecdysteroids)

Ecdysteroids (such as turkesterone) are chemicals plants produce to defend themselves against insects. These chemicals cause the insects to moult—it makes their exoskeletons fall off. What’s interesting is that these chemicals seem to have steroid-like effects in some small animals. Some ecdysteroids even have human trials showing their effectiveness. For example, this study found that a spinach extract containing small amounts of ecdysterone caused the participants to gain quite a bit of extra muscle mass and strength.

However, the highest quality study looking into ecdysteroids for building muscle found it had no effects on our hormones, muscle growth, or fat loss (study). As a result, the International Society of Sports Nutrition doesn’t recommend ecdysteroids or turkesterone as muscle-building supplements (study).

This lack of enthusiasm is mirrored by experts like Eric Trexler, Ph.D., who told us, “At this time, there is not sufficient evidence to suggest that turkesterone enhances increases in strength or muscle mass in humans.”

For more, we have a full article on turkesterone (and other ecdysteroids.


HMB performed suspiciously well in a couple of studies, showing steroid-like muscle growth. These studies are infamous in the muscle-building community because of how suspect they are. In fact, the disreputability of these HMB studies has even thrown shade over some of the studies looking into ketogenic diets, given that some of the same people were involved in that research as well.

Furthermore, since HMB is found within protein sources, it’s generally better just to optimize your protein intake.


The nitrates found in beets and leafy greens are knowing for being generally healthy, reducing muscle soreness, and even improving our lifting performance (study). However, there’s no need to supplement with nitrate. Most experts recommend eating more leafy green vegetables instead.

Collagen Powder

Collagen powder is known for increasing gains in lean mass. Not by improving muscle growth, though, but by causing extra growth in our connective tissues. This is certainly an interesting effect, and for those of us with cranky joints, it may even help, but for the average skinny guy who’s trying to gain weight, it’s not needed. After all, bulking up, in general, will improve the strength of our connective tissues. We don’t need to be trying to get extra hypertrophy there.

When it comes to muscle growth, a new study just came out showing that collagen powder can be effective for helping old people with sarcopenia (age-related muscle loss) gain more lean mass.

As with HMB, collagen is found within regular protein sources. For most of us, it’s better to focus on eating enough protein overall.


Arginine supplements can’t be digested properly and thus cannot be effective. Researchers learned this and found another way to get the intended effect, giving us citrulline malate instead. So if you’re interested in arginine, just take citrulline malate.

Baking Powder

Baking powder is beta-alanine’s evil twin. Baking powder mimics the effects of beta-alanine, making it an equally effective muscle-building supplement, but with all kinds of unwanted side-effects.

Not only will supplementing with baking powder make you feel incredibly sick and dehydrated, but a single dose also contains four times the recommended daily intake of sodium.

I tried taking baking powder as a pre-workout supplement and wound up spending my workout in the bathroom.

The Ectomorph Bulking Supplement Protocol

Illustration of a skinny guy building muscle and becoming muscular (before/after).

Supplements won’t make or break your bulking routine. The quality of your workouts and diet are far more important. However, supplements can still help. Of all the supplements out there, the very best bulking supplements for ectomorphs are:

  1. Creatine for the improved rate of muscle growth.
  2. Caffeine if you need a bit of extra energy before working out.
  3. Maltodextrin to make gaining weight easier.
  4. Whey protein to make it easier to eat enough protein.

Daily Creatine: Take 5 grams every day. A simple way to do this is to mix it into a glass of water and have it first thing every morning. I also like to mix a few grams into my workout shakes.

Training drink: 30-90 grams of whey protein (or other protein powder) + 60-180 grams of maltodextrin (totally optional!) + 5 grams of creatine.

The smaller dose is a fairly typical post-workout shake, and it will fully take care of all of the nutrient timing benefits (study). The larger dose turns it into more of a weight-gainer, which is great if you’re having trouble gaining weight.

You’d want to have this shake within 1-2 hours of training for optimal results (studystudy, study, study). Personally, I start sipping on it as I begin my workout, and then I chug whatever’s left when I finish my workout.  It tastes like sludge, but nothing will guarantee muscle growth like consuming tons of good calories and protein after a rigorous workout.

Illustration showing the Bony to Beastly Bulking Program

If you want more muscle-building information, we have a free bulking newsletter for skinny guys. If you want a full foundational bulking program, including a 5-month full-body workout routine, diet guide, recipe book, and online coaching, check out our Bony to Beastly Bulking Program. Or, if you want a customizable intermediate bulking program, check out our Outlift Program.

Shane Duquette is the co-founder and creative lead of Outlift, Bony to Beastly, and Bony to Bombshell, and has a degree in design from York University in Toronto, Canada. He's personally gained sixty pounds at 11% body fat and has nine years of experience helping over ten thousand skinny people bulk up.

Marco Walker-Ng is the co-founder and strength coach of Outlift, Bony to Beastly, and Bony to Bombshell, and is a certified trainer (PTS) with a Bachelor's degree in Health Sciences (BHSc) from the University of Ottawa. His specialty is helping people build muscle to improve their strength and general health, with clients including college, professional, and Olympic athletes.